Hand-opening sheet metal end closure



Dec. 10, 1968 w. T. SAUNDERS 3,415,411

HAND-OPENING SHEET METAL END CLOSURE Filed Dec. 1966 INVENTOR WILLIAM T.SAUNDERS SM-A -LWQ ATTORNEY United States Patent 3,415,411 HAND-OPENINGSHEET METAL END CLOSURE William T. Saunders, Weirton, W. Va., assignorto National Steel Corporation, a corporation of Delaware Filed Dec. 6,1966, Ser. No. 599,442

1 Claim. (Cl. 220-54) ABSTRACT OF THE DISCLOSURE An improvedhand-openable metal end closure in which an elongated tab opener issecured to the end closure to provide class 1 lever action for punctureof the end closure along a preformed scoreline. The tab opener has awedge-shaped configuration at its puncturing end. Portions of the tabopener forming the wedge-shaped configuration cross the scoreline andprevent puncturing beyond a desired limit and spread sheet metal alongthe scoreline to make possible removal of the punctured portion of sheetmetal from the remainder of the end closure without binding along thescoreline.

This invention is concerned with an improvement of hand-openable, sheetmetal end closures for containers.

More specifically, this invention is concerned with improvement of handopeners which rely on class 1 type lever action as described inapplicants co-pending application S.N. 495,796, entitled, ContainerStructure and Manufacture, filed Oct. 14, 1965. With this type of handopener a securing means, such as a rivet, is used for securing a tab(handle) to a sheet metal end closure. The rivet acts as a fulcrum for aclass 1 lever which initiates puncture of the end closure. While thisstructure provides easy hand operation, it has been found that, with thehigh mechanical advantage available for puncturing a sheet metal endclosure because of applicants earlier invention, a greater portion ofthe sheet metal to be removed from the end closure is forced downwardlybelow the level of the remaining portion of the sheet metal in the endclosure than is desired. When this portion of sheet metal is pulledbackwardly to complete opening of the container, it binds with theperiphery of the puncture for-med in the end closure and, for aninstant, impedes completion of opening.

The contribution made by the present invention acts to spread sheetmetal at the periphery of the end closure puncture to overcome anypossibility of binding and sets definite limits on the puncture formedwhich stabilizes positioning of the fulcrum.

In describing a specific embodiment reference will be had to theaccompanying drawings wherein:

FIGURE 1 is a portion of a hand-openable end closure with its tab openerlocated within a scoreline as described in applicants earlier patentapplication referred to above,

FIGURE 2 shows the hand opener of FIGURE 1 in a partially open positionafter puncture of the end closure,

FIGURE 3 is a portion of a hand openable end closure embodying theinvention,

FIGURE 4 shows the embodiment of FIGURE 3 in a partially open positionafter puncture of the end closure, and

FIGURE 5 is an enlarged showing of a portion of the structure of FIGURES3 and 4.

Referring to FIGURE 1, rivet secures tab opener 12 to a scored portion14 defined by scoreline 16 on a sheet metal end closure. It should benoted that tab opener 12 is located entirely within the scoreline 16 sothat a perpendicular projection of tab opener 12 on scored por- 3,415,41I Patented Dec. 10, 1968 tion 14 falls entirely within scoreline 16.While this has a numberof advantages as set forth in applicants earliermentioned patent application, it also has anumber of disadvantagesrelated to binding of sheet metal along the scoreline after puncturewhich. will be discussed in relation to FIGURE 2.

Referring to FIGURE 2, which shows the structure of FIGURE 1 afterpuncture of the and closure, it will be seen that the class 1 leveraction resulting from lifting of end 20 of tab 12 causes puncturing end22 of lever 12 to penetrate into the container. It has been found thathecauseof the, mechanical advantage provided by thislever action,puncturing end 22 penetrates the container more than desired, e.g.,beyond rivet 10, causing bending of the scored portion 14 along dottedline 24.

In order to complete removal of the scored portion 14, tab opener 12must be pulled backwardly in a direction opposite to that of thepuncture. When attempting to remove the punctured portion of the scoredsheet metal it has been found that binding occurs at points 26 and 28,such that easy removal is impeded. The present invention which will bedescribed in relation to FIGURES 3 through 5 overcomes thesedisadvantages of the type of hand opener shown in FIGURES 1 and 2.

Referring to FIGURE 3, elongated tab opener 30 is secured to a scoredportion 32 of an end closure by rivet 34. Tab opener 30 includes anarrow-width curvilinear edge 36 and an opposite longitudinal end 38which has a substantially wider configuration.

The narrow-width curvilinear edge 36 increases in width along legs 39and 40 to present a wedge-shaped configuration with the wedge openingtoward longitudinal end 38.

Referring to FIGURE 4, the class 1 lever action produced by lifting onend 38 causes narrow-width end 36 to break sheet metal along the curvedconfiguration scoreline portion 42. However, legs 39 and 40 of the wedgeshaped configuration of the tab opener cross the scoreline at points 44and 46 and supplement the fulcrum action of rivet means 34, that is legs39 and 40 act to stabilize the position of the fulcrum of the class 1lever along the longitudinal axis of the tab opener 30. Further, legs 39and 40, in crossing of the scoreline, spread metal at the periphery ofthe puncture and prevent penetration of end 36 to the extent shown inapplicants earlier embodiment shown in FIGURE 2. i

As shown in FIGURE 5, legs 39 and 40 crossing the scoreline at points 44and 46 cause sheet metal along the scoreline to bulge outwardly, that isaway from the opening, at these points. Therefore, upon pulling back tabopener 30 to complete opening of the container there is no binding ofthe sheet metal which has penetrated below the surface of the remainderof the sheet metal blank with metal along the periphery of the puncture.Absence of binding makes possible the complete removal of the scoredportion of the end closure in a smooth succession of steps.

While the embodiment shown depicts a ring-pull tab opener and apour-opening scoreline, it is understood that the invention is notlimited to these embodiments since a tab opener of other configurations,such as a generally rectangular configuration with the wedge-shapedconfiguration can be used with either a pour-opening end closure and thescoreline configuration can extend around the circumference of the endclosure to provide a fullopen end closure. Also the teachings of theinvention are applicable to any of the conventional sheet metals usedfor making metallic end closures.

What is claimed is:

1. Hand-openable sheet metal end closure for a container comprising asheet metal blank, 1 an elongated tab opener means having a narrow-widthlongitudinal end and a remaining longitudinal end, the narrow-width endhaving a curvilinear edge conopener means to the scored area of thesheet metal blank, the tab opener means being thus secured to the sheetmetal blank so as to constitute a class 1 lever with the means forsecuring the tab opener figuration from which the width of the tabopener 5 means acting as a fulcrum so that the curvilinear meansincreases to define a wedge-shaped configuraedge narrow-widthlongitudinal end of the tab opener tion opening in the direction of theremaining longimeans punctures the sheet metal blank and forces atudinal end of the tab opener means, portion of the scored area of thesheet metal downa scoreline of diminished metal thickness in the sheetwardly below the remainder of the sheet metal blank metal blank definingan area to be removed by the by a lifting action at the remaininglongitudinal end tab opener means, the scoreline having a curvilinear ofthe tab opener means, with the wedge-shaped porportion for initiatingremoval of the area defined by tion of the tab opener means acting tospread sheet the scoreline from the sheet metal blank, and metal alongthe scoreline of the sheet metal blank means for securing the tab openermeans to the scored for easy removal of sheet metal extending downareaof h sheet t l blank, such means being [0- wardly below the remainder ofthe sheet metal blank.

' cated within the area defined by the scoreline contiguous to thecurvilinear portion for initiating removal of the area defined by thescoreline, so that a perpendicular projection of the curvilinear edge ofReferences Cited UNITED STATES PATENTS the narrow width longitudinal endof the tab opener 3250426 5/1966 Fr'aze 220-54 means lies within andsubstantially parallel to the 3,341,055 9/1967 Radford 220-554 3,342,3679/1967 Irland 220-54 contiguous curvilinear configuration portion of thescoreline and such that a perpendicular projection of the wedge-shapedconfiguration portion of the tab THERON ONDON, Przmary Exammer.

opener means crosses the scoreline adjacent to and GEORGE T HALL,Assistant Examiner. on opposite sides of the means for securing the tab

